


it's cute in a way

by mr_charles



Category: Star Trek: Alternate Original Series (Movies)
Genre: Alternate Universe, F/M, Genderbending, Medical Kink, Menstruation Kink, Mildly Dubious Consent, Oral Sex, always-a-girl!Chekov
Language: English
Status: Completed
Published: 2013-12-26
Updated: 2013-12-26
Packaged: 2018-01-06 04:48:08
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,021
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1102592
Author URL: https://archiveofourown.org/users/mr_charles/pseuds/mr_charles
Summary: <blockquote class="userstuff">
              <p>Polina's biggest shame is McCoy's biggest turn-on. </p><p>(or the one with the underage and the menstrual kink)</p>
            </blockquote>





	it's cute in a way

**Author's Note:**

> title from she wants revenge's "tear you apart"
> 
> un-beta'd and all mistakes are mine
> 
> I welcome corrections if anything is off

It happens when Polina is 15. She goes with a few classmates to a party off-campus and ends up in a back room with an older boy. His kisses are too forceful for her liking but she likes the way his blonde stubble rubs against her neck and the throaty way he groans her name. His fingers are cold as they trail up her pale thigh into her skirt and before she can say something, he jerks away from her. His mouth is turned in disgust.

“Fuck! Were you going to tell me that you were on the rag?” His fingers are smeared with red.

“I…” she starts, absolutely mortified. _It’s early_ she wants to say but he’s already out and slamming the door behind him.

The stares and whispers follow her on campus and in class but by the time her next cycle starts, the chatter has died down and the gossipers have found someone new to focus on.

 

She avoids boys for the longest time. It’s not hard; she gets assigned to the Enterprise, gets to wear a gold dress that’s too short in her opinion, and nurses an awkward crush on the captain. But life is good for Polina Chekova. She takes the regulated hormones that Nurse Chapel gave her while she was still a student. She only gets her cycle three times a year, which is great if you’re planning on being in space for five years at a time.

(she wonders briefly if she can stay on the pills forever; she never wants a repeat of the Party Incident)

One night, or technically early morning, she’s up in her quarters writing letters home to her family. _You should be in bed, Polina_ she chides herself as she finishes up a fourth letter. Her pen skitters across the paper as a sharp pain shoots through her lower abdomen. She cries out in Russian as it throbs through her; like cramps only magnified over a hundred percent.

In her sleep shorts and thin tank-top, she stumbles to the med bay, half convinced she’s dying. It’s her appendix, probably. Or her stomach has burst. Or it’s her stomach and her—

“Ensign!” Doctor McCoy startles her. “What are you doing here this time of night?”

“I…” Polina swallows. “Is Nurse Chapel here?”

“Just me, kid,” he says, eyeing her warily. “What is it, ensign?”

“It’s, um, a feminine matter.” Her voice is low and she’s staring directly at the floor.

With a raised eyebrow, he points her to a small exam room. “There’s a gown in there. Someone will be in there shortly.”

As she closes the door, Polina is thankful the gown isn’t paper. Goosebumps prickle on her skin as she realizes she didn’t put her bra back on before she left but as she pulls her shorts off, she realizes that her lack of bra is the least of her problems.

The crotch of her shorts is soaked through and sticky with blood. Her panties are in the same situation; both are probably ruined. Panic surges through Polina, a constant stream of _no no no no no no_ as McCoy opens the door.

“What happened?” His voice is rough and Polina tries not to cry.

“Nurse Chapel gave me the pills and the pills worked and I only bled every four months and I—“

“Shit.” McCoy is scowling now. “Ensign, how long have you been on those pills?”

Polina tries to remember. It was shortly after the Party Incident and her 18th birthday is in only a few months…

McCoy takes her silence as ignorance. He swears under his breath. He gestures vaguely to the cupboards behind her. “There’s some…stuff…in there. Clean stuff. Clean up and let me know when you’re decent.” He shuts the door behind him.

Polina sobs and curses as she pulls the smallest pair of generic cotton panties out of the drawer. She uses wet paper towels to wipe the worst of the mess off her thighs. There are even smudges on her knees. The small pads in the bottom drawer seem like a ridiculous option considering her situation but they’re better than nothing.

Kind of.

“Doctor?” she says, poking her head out of the door. She sounds like a scared little girl. She’s wrapped herself in the faded blue hospital gown. McCoy looks torn between pity and annoyance.

“Lay down, Ensign.” Polina situates herself on the hard cot, flushing red. “Are you sexually active?”

Polina shakes her head. “No, Doctor.” She gasps quietly as McCoy presses his gloved fingers lightly into her lower abdomen.

“Why are you on birth control?”

“My periods,” Polina says. “I… I don’t like them.”

“Unfortunate academy gym class incident?” he snorts, looking at the scanner above her head.

“There was a boy,” she says before she can stop herself. “He wanted to but I was bleeding and he… made fun of me.”

McCoy frowns, a look of confusion crossing his features. They’re nice features, Polina thinks, as he scans her. “Ridiculous,” he mutters to himself. “A real man should be able to appreciate a woman. A real man should appreciate _all_ of a woman.”

“Doctor?” Polina asks, not sure if he’s talking to her or not.

He snaps out of his reverie and clears his throat. “No more pills. Not until I say so. Your reproductive system is all shot to Hell and needs a good six months to reset itself.” At the panic in her eyes, he says, “You won’t bleed like this constantly. I’m going to give you a sedative and have you spend the night here so I can monitor you overnight. Is that alright?”

She nods quickly, panic turning into dread. What if, in six months, she meets someone? What will she do then? Tell them to come back in a few months? A quick injection to her neck has her settling back into the cot, eyelids fluttering. Her last thought is of the doctor covering her with a blanket.

 

Polina isn’t sure what time it is when she wakes up. But Doctor McCoy is there, checking her vitals. “Mornin’,” he says gruffly. “How are you feeling?”

“Sore,” Polina says finally. She’s never been beaten up but she feels like she’s been kicked between the legs repeatedly.

“I’ll need to do a physical examination,” he says as he pulls a pair of gloves on.

“Examination?” Polina has had enough embarrassment in the last day to last her a lifetime.

“Relax,” he says. “I’ve seen it all between Jim and med school.” He reaches for her but pauses. “I think you can do that on your own.”

“Thank you,” she snaps as she slides the panties down and off. The bleeding has stopped. Sort of. But Polina feels like she needs a shower and a good scrubbing.

Polina has had a gynecological exam before, from Nurse Chapel. She’d been chipper and chatty and distracted Polina from the fact that she was naked from the waist down while Nurse Chapel took swabs and samples.  

But here? With her feet in stirrups? And Doctor McCoy “hmm”-ing and muttering between her spread legs? Oh, Polina feels like she’s about to die of mortification. Her toes curl in surprise as he parts her folds to examine her. A moan tries to bubble out of her throat when he swipes his thumb over her clit. She’s so sore that she’s sensitive. Or maybe she’s so sensitive that she’s sore. He swipes his thumb once, twice, three times more before Polina finally groans.

“Do you want me to stop?” he asks. “Polina?”

She shakes her head, curls catching on the cot. “Doctor…”

She hears him chuckle as he presses his thumb against her. “That’s a girl,” he murmurs. “Look at you, all red and wet.” Polina makes a high noise. “Come on, baby girl. Let me hear you. All slick and ready. I could pull my cock out and fuck you right now. Oh Polina. You’d be so tight, wouldn’t you?” His thumb rubs her clit in tight circles.

Images flash through Polina’s mind. She wants him to lean down and lick her clean. She wants him to fuck her—to get them both bloody— “Fuck!” Polina pants as she comes. The orgasm burns through her like fire and McCoy rubs her through it.

She’s still coming back down when he takes her legs out of the stirrups. His hands waver slightly as he pulls his gloves off and disposes of them. “One of the girls brought you some clean pajamas this morning when she heard you were here,” he says stiffly, gesturing to a pile of clothes on the chair in the corner. “And you’ve got the next two days off.”

“Thank you, Doctor,” she says as she slides her panties back on. “For everything.” His cheeks flush a pleasant pink at her words before saying “anytime” on his way out of the room.

 

Three months pass before she goes to McCoy again and even then it’s for something unrelated. A landing party incident had her sliding off a pile of rocks and scraping her hands up badly. She and McCoy make small talk as he fixes her up. She’s about ready to go when he clears his throat.

“Are you bleeding anywhere else, ensign?” She flushes. He smirks at her. “I’ll be by after my shift.”

Polina paces in her quarters. She’s already showered and shaved and even tried to tame her hair. She put lipstick on, wiped it off, and reapplied it before wiping it off again. She’s changed into a nightshirt but it makes her look younger than she really is. She’s about to change when she hears McCoy at her door.

He bursts in quickly and she’s about to ask if he changed his mind before he says “I shouldn’t let anyone see me in the 17 year old ensign’s quarters after hours.” Then his mouth is on hers and Polina is more focused on the stale coffee taste of him than her own nerves. He murmurs filthy things in her ear as one hand cups her small ass, pushing her into him. She can feel how hard he is and she thinks _I did that_.

Polina ends up on her bed with her nightshirt pushed up to her stomach. McCoy heads into her bathroom and comes back with a towel. “I plan on making a mess,” he promises as he slides the towel under her hips. He lies down on her bed and places one of her long legs over his shoulder before he presses kisses to her sharp hipbones, fingers playing with the elastic of her panties.

“Doctor, I didn’t…” she starts as he starts kissing her through her panties. There’s already a red spot blooming on the pale cotton.

“Good girl,” he breathes against the cotton. With a firm tug, the panties are around her knees and then cast off on the floor by her bed. He holds her hips to the bed as he flicks his tongue against her. Her immediate reaction is to try to buck but his grip tightens. He makes obscene noises as he sucks at her, tastes her—tastes _all_ of her. He laps at her core and Polina glances down to see the red smeared all over his nose, mouth, and chin.

His eyes are cloudy when he glances up at her and she can see how he’s thrusting shallowly against her bed. She wants to offer some relief but he’s back at her core with his thumb rubbing against her clit and all she can think of is to chase her release.

When she comes, it’s with a deep groan of satisfaction. McCoy keeps licking at her until she feebly kicks at him. He wipes his face on the towel under her before heading into the bathroom. She can hear him washing his mouth out with her mouthwash. She looks down between her thighs to see the red staining the towel. Something inside her heats up. _I could do this every month_ she thinks as McCoy comes back out of the bathroom. 

**Author's Note:**

> the title was almost "written in blood" and I dedicate this to my ever-lovely Nina
> 
> this isn't my first foray into menstrual kink and if you can find it on the depths of LiveJournal, you win a cookie


End file.
